Back to EveryPatent.com
United States Patent |
5,105,455
|
Kato
,   et al.
|
April 14, 1992
|
X-ray diagnostic apparatus
Abstract
A protection cover includes a pressure responsive means mounted within the
cover along its inner wall surface and which operates responsive to
external forces to be exerted upon contact with a neighboring object. The
protection cover is provided at a portion where physical contact may occur
between any of movable or rotating component devices of an X-ray
diagnostic apparatus, such as, an X-ray exposure unit or an image
intensifier, and a neighboring object which is in the path of the
component devices, such as, a subject or a catheter table. The protection
cover may, for example, be provided at a moving end of a component X-ray
diagnostic apparatus, such as, the forward end of the image intensifier,
or may be mounted, instead of being mounted on a movable component device,
on a neighboring object at its side facing to the movable part of the
component devices, such as, a stand section of the catheter table, which
lies in the path of a moving part of the X-ray radiographing component
devices.
Inventors:
|
Kato; Kunitaka (Utsunomiya, JP);
Narita; Sukekiyo (Ootawara, JP);
Gunji; Teruomi (Ootawara, JP)
|
Assignee:
|
Kabushiki Kaisha Toshiba (Kawasaski, JP)
|
Appl. No.:
|
603364 |
Filed:
|
October 26, 1990 |
Foreign Application Priority Data
| Oct 30, 1989[JP] | 1-279872 |
| Nov 15, 1989[JP] | 1-294877 |
Current U.S. Class: |
378/117; 250/227.16; 378/95 |
Intern'l Class: |
H05G 001/54 |
Field of Search: |
378/95,114,117
250/227.16
340/555.590
|
References Cited
U.S. Patent Documents
4358856 | Nov., 1982 | Stivender et al. | 378/197.
|
4482890 | Nov., 1984 | Forbes et al. | 250/227.
|
4733408 | Mar., 1988 | Beikuefner et al. | 378/117.
|
4969170 | Nov., 1990 | Kikuchi et al. | 378/145.
|
Primary Examiner: Howell; Janice A.
Assistant Examiner: Wong; Don
Attorney, Agent or Firm: Oblon, Spivak, McClelland, Maier & Neustadt
Claims
What is claimed is:
1. An X-ray diagnostic apparatus comprising:
a rotation arm having a pair of mutually confronting arm units;
X-ray radiographing component devices mounted on forward ends of said arm
units and movable about a subject lying on a catheter table by rotating
the rotation arm about the catheter table, where the X-ray radiographing
component devices include an X-ray exposure unit and an image intensifier,
the X-ray exposure unit being mounted on a forward end of one of the arm
units, and the image intensifier being mounted on a forward end of an
other of the pair of arm units;
elastic protection covers disposed in a path of travel of the X-ray
exposure unit and the image intensifier; and
pressure sensors located along inner surfaces of the protection covers and
which are operative by sensing an external force to stop a rotation of the
rotation arm, wherein said pressure sensor is formed of an elastic optical
fiber having flexibility, the elastic optical fiber including an elastic
core having a high refractive index, an elastic clad overlying the elastic
core and having a low refractive index, and a cover surrounding an outer
surface of the elastic clad.
2. The X-ray diagnostic apparatus according to claim 1, wherein a film
changer is provided at the image intensifier, a protection cover formed of
an elastic material is disposed in the travel path of the film changer,
and the pressure sensors are disposed along the inner wall surface of the
protection cover disposed in the travel path of the film changer.
3. The X-ray diagnostic apparatus according to claim 1, wherein a
protection cover formed of an elastic material is disposed at a contact
portion of the catheter table which has a possibility of contacting the
X-ray radiographing component devices, and the pressure sensors are
mounted along an inner wall surface of the protection cover disposed at a
contact portion of the catheter table.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to X-ray diagnostic apparatuses and, more
particularly, to an X-ray diagnostic apparatus provided with safety means
which senses physical contact between component devices, such as an X-ray
exposure unit and an image intensifier, and peripheral objects located in
surrounding areas and which stops the operation of the X-ray diagnostic
apparatus upon occurrence of such contact.
2. Description of the Related Art
An X-ray diagnostic apparatus of the type mentioned for use in medical
diagnosis is known wherein a rotation arm of substantially a letter
C-shaped configuration having a pair of confronting arm units is mounted
on a rotating support secured to a wall or ceiling, and component members
typically including an X-ray exposure unit, an image intensifier, etc. are
respectively disposed on free ends of the arm units. Adjacent the arm
support side of the X-ray diagnostic apparatus is placed a catheter table
having thereon a lengthwisely slidable top plate on which a subject to be
examined or diagnosed is placed. The rotation arm is rotatable in a
horizontal direction with the rotation of the rotating support and is
rotatable also about its own axis at a point at which it is mounted to the
rotating support. Further, the rotatable support is vertically movable to
provide for position adjustment. In the X-ray diagnostic apparatus so
constructed, an X-ray diagnostic operation may take place by rotating the
rotation arm in relation to the rotation of the rotating support or
rotating the same about its own axis, thereby to permit the above
component devices to move to a desired location around the subject lying
on the top plate of the catheter.
In operating the X-ray diagnostic apparatus, it frequently occurs that the
component devices, as they rotate or travel, come into contact with
peripheral objects including, for example, a top plate of the catheter
table, its support stand, monitoring equipment, as well as moving objects
including a subject and an operator, that lie in the path of the movable
component members.
Safety measurements taken in a conventional device of the type mentioned
provide for contact switches in the path of moving component members, the
sensor switches being operative upon occurrence of contact between them
and an peripheral or neighboring object to stop or fault the operation of
the rotation arm, thus attaining safety in operation and avoiding damages
arising out of the contact.
The known contact switch is constructed by a tape switch attached to the
rear surface of a resin or metallic cover mounted, via spring means, on a
component member, such as, the forward surface of an image intensifier,
and a dogg projecting from the same surface at a side opposite the tape
switch, in such a manner that the tape switch and the dogg are held in
connection or disconnection by external forces applied to the cover. This
arrangement, however, involves the following drawbacks.
1. The drive of the switch is by a spring force, so that it is difficult to
make adjustment and the operation of the switch is not stable.
2. The operation of the switch is limited regarding a direction in which
forces are applied. The switch is less effective against forces that are
applied in directions other than a direction in which the switch and the
dogg face each other.
3. The construction of the cover having the switch is complicated and does
not provide a good touch in the event a subject contacts the cover.
SUMMARY OF THE INVENTION
This invention has been achieved to remove the drawbacks above mentioned
and has for its object to provide an X-ray diagnostic apparatus having
sensor switch means which is capable of positively operating against
external forces acting in all directions, attaining both safety in
operation of the diagnostic apparatus and prevention of accidents due to
contact between component members of the device and a neighboring object,
and yet providing for a greatly softened touch to a moving object in the
event of contact.
To achieve the foregoing object, the apparatus according to this invention
provides, in an X-ray diagnostic apparatus comprising a rotation arm
having a pair of mutually confronting arm units, and X-ray radiographing
component devices mounted on free ends of the arm units and wherein an
X-ray photographing operation takes place by rotating the rotation arm
about a catheter table and thereby moving the X-ray radiographing
component devices around a subject lying on the catheter table, an X-ray
diagnostic apparatus further comprising an elastic protection cover or
covers provided in the path of the radiographing component devices, and a
pressure sensor provided within the protection cover along its inner wall
surface and which is operative to terminate the movement of the rotation
arm upon detection of external forces.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other features and objects of the present invention and
the manner of attaining them will become more apparent and the invention
itself will be best understood by reference to the following embodiment of
the present invention taken in conjunction with the accompanying drawings,
wherein:
FIGS. 1 to 4 show an X-ray diagnostic apparatus according to one embodiment
of the invention;
FIG. 1 being a front elevation schematically illustrating the construction
of the apparatus;
FIG. 2 being a side view of an image intensifier, a component device used
in the above apparatus;
FIG. 3 being an enlarged front elevation of a section A of FIG. 2;
FIG. 4 being a vertical cross section of an elastic optical fiber unit; and
FIG. 5 is a schematic block diagram showing the function mechanism of a
pressure sensor incorporating the elastic optical fiber unit of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
One embodiment of the invention will be described with reference to FIGS. 1
to 5.
Numeral 1 in FIG. 1 denotes a rotation arm, mounted on a rotating support a
installed on a floor base, and which is rotatable with the rotation of the
rotating support a in a horizontal plane tangentially intersecting the
axis of the rotating support a. The rotation arm itself is also rotatable
about its own axis of mounting. Numeral 2 is a catheter table similarly
mounted on the floor base and on which a top plate 2a on which a subject b
may be placed is mounted slidably in a longitudinal direction.
The rotation arm has at its free ends a pair of confronting arm units 1a
and 1b whereby the entire structure defines substantially a letter
C-shaped configuration. On the forward or free ends of the arm units are
respectively mounted X-ray radiographing component devices including, for
example, an X-ray exposure unit having an X-ray tube 3 and a movable X-ray
collimator 4 on the arm unit 1a, and an image intensifier 5 on the other
arm unit 1b in the illustrated embodiment. Each of these component devices
is rotatably supported with respect to one of the arm units so that its
angle of inclination and a direction in which it lies may be optionally
adjusted. The reference numeral 7 shows a film changer attached to the
image intensifier 5.
Numeral 6 is a contact sensor switch equipped for an X-ray radiographing
component device, and which may be located, for example, on the forward
end of the image intensifier 5 as shown in FIG. 2.
A specific arrangement of the sensor switch 2 is shown in FIG. 3 (an
enlarged view of a portion A in FIG. 2). As shown, the sensor switch 2
includes a ringshaped protection cover 12 secured at the forward
circumferential edge of the image intensifier 5 via a mounting metal 11.
In the inner wall surface are disposed a plurality of elastic optical
fiber units 13 having flexibility, which run along the inner wall of the
image intensifier 5 in the form of stripes parallel to each other in fixed
spacings.
The protection cover 12 is formed of an elastic material, such as rubber.
The optical fiber units 13 have, as shown in FIG. 4, a three-layer
structure having a core 14 formed, for example, of silicone rubber
material of a high refractive index, a clad 15 formed, for example, of
silicone rubber material having a low refractive index, overlying the core
15, and a coating 16, for example, of fluoro rubber coating the outer
surface of the clad 15.
As shown in FIG. 5, the optical fiber unit 13 is connected at one end to a
light source 17 and at the other end to a light reception element 18, the
light source 17 and the light reception element 18 being respectively
disposed via optical lens. The light reception element 18 is connected to
a controller 20 and a driver 21 via an amplifier 19, so that a
photoelectric conversion signal outputted by the light reception element
18 is fed to the controller 20 via the amplifier 19. An output signal from
the controller 20 causes the driver 21 to be operative to drive the
rotation arm 1.
A sensor switch 6 provided at the forward end of the X-ray collimator 4 of
the X-ray tube 3 has the same construction as above.
When external forces are applied in the above mentioned arrangement, is
applied, for example, to the protection cover 12 mounted on a forward
circumferential edge of the image intensifier 5, the protection cover 12
is subjected to elastic deformation which in turn causes the optical fiber
units 13 to undergo elastic deformation. This results in disordering
conditions for total reflection of the fibers and decreasing the quantity
of light to be transmitted. The decrease in the transmission of light is
sensed by the light reception element 18 attached to one end of the
respective optical fiber units 13. A photoelectrically converted output
signal from the light reception element 18 is transferred to the driver 21
via the signal processing circuit elements shown in FIG. 5, thereby to
stop the operation of the rotation arm. Accordingly, when any neighboring
object, such as, the subject or the top plate or support platform of the
catheter table is brought into contact with the forward end of the image
intensifier 5 or the X-ray collimator 4, such contact is immediately
sensed by the sensor switch 6 to stop the operation of the X-ray
diagnostic apparatus, whereby damages due to contact between the component
devices and a neighboring object may be avoided. The protection cover and
the optical fiber units that have been once deformed by external forces
may restore their original state so as to be ready for subsequent
operation.
According to this embodiment, since the sensor switch 6 is formed by the
elastic protection cover 12 and the elastic optical fiber units 13 mounted
along the inner surface of the protection cover 12, an external force
exerted thereon from any direction can be sensed at high sensitivity, thus
providing for stable switching functions. Moreover, when the subject
happens to come into contact with the protection cover, the touch is so
soft that no disagreeable feeding may be generated to the subject or the
operator.
Although the sensor switch 6 is provided at a forward end surface of the
movable X-ray collimator 4 and of the image intensifier 5 in the foregoing
embodiment, it may be provided at the forward end surface of the film
changer to sense contact between it and a subject b. It may also be
provided at the support stand 2 of the catheter table 2 or at any
neighboring equipment or devices, such as, around monitoring equipment,
not shown, suspending from the ceiling.
Further, in the foregoing embodiment, while the elastic optical fiber units
13 have been used as the pressure sensing means, similar effects and
functions may be attained by mounting strain gages in the inner wall of
the protection cover 12 in place of the sensor switch units in the same
manner as the optical fiber units. In this case, the light reception
element 18 may be replaced by conversion means which detects changes in
electrical resistance due to strains and which generates electrical
signals.
Additional embodiments of the present invention will be apparent to those
skilled in the art from consideration of the specification and practice of
the present invention disclosed herein. It is intended that the
specification and examples be considered as exemplary only, with the true
scope of the present invention being indicated by the following claims.
Top